Renewable hammer head of the two-way reversible type



June 12, 1956 'H. B. REINHARDT 2,750,124

RENEWABLE HAMMER HEAD OF THE TWO-WAY REVERSIBLE TYPE 2 Sheets-Sheet 1 llllrn mm Filed May 6, 1953 IN V EN TOR. Hen/y Ema/r4 jfeazkardi,

June 12, 1956 H. B. REINHARDT 2,750,124

RENEWABLE HAMMER HEAD OF THE TWO-WAY REVERSIBLE TYPE 2 Sheets-Sheet 2 Filed May 6. 1953 INVENTOR. Henry bmwizhzz/zarafi United States Patent Oflice 2,750,124 Patented June 12, 1956 RENEWABLE HAMMER HEAD OF THE TWO-WAY REVERSIBLE TYPE Henry Brown Reinhardt, Flossmoor, 11]., assignor to American Brake Shoe Company, New York, N. Y., a corporation of Delaware Application May 6, 1953, Serial No. 353,311

4 Claims. (Cl. 241-197) The invention relates to new and useful improvements in rotary impact hammers of the type used in rock crushers, pulverizers and similar mills, and has reference more particularly to a renewable and reversible hammer head or tip whereby uniform Wear on the impact surfaces and edges thereof can be obtained.

An object of the invention resides in the provision of an improved hammer structure for the purposes described consisting essentially of a shank and a hammer head and wherein the head, although removable from the shank and reversible thereon, so as to subject other surfaces to Wear, is additonally constructed and arranged to provide complete protection for the end of the shank.

A more specific object of the invention is to provide a hammer head having a recess or cavity therein of a shape in plan complementary to the cross sectional shape of the shank end adapted to be inserted in the cavity, whereby the parts have a secure interfitting relation, and wherein the shape of the cavity is symmetrical with respect to a center line to permit end for end reversibility of the head.

Figure 8 is a horizontal sectional view taken substantially along line 8-8 of Figure 7.

Referring to the drawings, and particularly Figures 1, 2 and 3, the embodiment of the invention selected for illustration in these figures includes a shank 10 having a shaft receiving opening 11 and an intermediate ledge or flange portion 12 positioned immediately above the head receiving end 14. The terminal end of the shank is wedgeshaped to thus provide an apex 15 and said shank end has side portions 16 and 17, Figure 2, of reduced width, the same being formed by diagonal surfaces 18 located at all four corners of the shank end and extending vertically thereof. The said shank end 14 thus presents a special shape in cross section, see Figure 2, and the hammer head 20, designed for association therewith, is recessed to provide a cavity 21 of complementary shape in plan. The opening for the recess or cavity in the hammer head is located in the top wall 22 of the head and since the cavity terminates short of the bottom wall 23, the said bottom wall remains imperforate to thus provide adequate protection for the shank end.

The said shank end 14 of special shape in cross section, as described, is provided with key receiving grooves 24 and 25 formed in the side portions 16 and 17, respectively, the grooves receiving the keys 26 and 27. Laterally extending openings 28 and 29 are formed in the hammer 7 head, the same intersecting the cavity 21 within the ham- Another object resides in the provision of novel means for locking the hammer head in assembled relation on the shank and which said means are readily removable for removing the head. Thus reversibility of the head is possible and also the head can be renewed in the event it is completely worn out without disturbing the relation of the shank on its driving shaft.

A further object is to provide a combination hammer head and shank wherein the head is provided with a cavity for receiving the formed end of the shank so that the shank end is protected during use.

With these and various other objects in view, the invention may consist of certain novel features of construction and operation, as will be more fully described and particularly pointed out in the specification, drawings and claims appended hereto.

.In the drawings which illustrate an embodiment of the device and wherein like reference characters are used to designate like parts Figure 1 is a view in side elevation illustrating a rotary impact hammer and shank structure embodying the improved features of the invention;

Figure 2 is a horizontal sectional view taken substantially along line 22 of Figure 1;

Figure 3 is an elevational view of the shank end having a special formation in cross section and on which the hammer head is adapted to be assembled;

Figure 4 is a fragmentary side elevational view of a modified form of hammer structure coming within the invention;

Figure 5 is a horizontal sectional view taken substantially along line 5--5 of Figure 4;

Figure 6 is another form of hammer structure coming within the invention, the same being shown in side elevation;

Figure 7 is a vertical sectional view taken substantially along line 7--7 of Figure 6; and

mer head and the channels 30 on respective sides of the hammer head. When the hammer head is mounted on the shank end the openings 28 and 29 therein align with the grooves 24 and 25, respectively, and the keys 26 and 27 are inserted in said aligned openings and grooves for the purpose of releasably securing the head to the shank end. The keys may be held in place by cotter pins 31, which pins are received within the channels 30, previously described.

The hammer head of Figures 1, 2 and 3 is reversible, face for face, on its shank. The keys 26 and 27 can be easily removed from the aligned openings and grooves and with the removal of both keys the head will drop from the shank. During use of the combination shank and hammer head the keys are adequately shielded and protected against excessive wear and deterioration and in accordance with the invention the end 14 of the shank is also fully protected against wear since the cavity terminates within the head and the bottom wall protects the said shank.

The modification of Figures 4 and 5 differs in one major respect, namely, the keys are bent at their ends for locking them in place. The shank end 40 is provided with the ledge 42 below which depends the shank end 44. The said shank end is approximately square in cross section, as best shown in Figure 5, and the hammer head 50 is recessed as at 51 to provide an opening of approximately the same size and shape as the shank end for accommodating the same. The hammer head 50 is formed with arcuate top and bottom surfaces 52 and 53, with the top surface having the opening therein leading to the cavity or recess 51. With the parts in assembled relation the hammer head is releasably held to its shank end by means of keys 56 and 57, the said keys being inserted in aligned grooves and openings in the shank end and head, respectively. The grooves are identified by numerals 54 and 55, the same being formed in the respective side walls of the shank end, whereas the openings in the head are identified by numerals 58 for the key 56 and 59 for the key 57.

In the modification of Figures 4 and 5, instead of using cotter pins to lock and retain the keys in place, said keys are tapered at their respective ends and the ends are bent around the corners of shank 44. The tapered bent ends of the keys are indicated by numeral 61 and for accommodating the said bent ends, the openings 58 and 59 in the head are somewhat enlarged in size as at 60. Here again the hammer head has two-way reversibility and it is relatively easy to remove the head for reversing the same :since it merely requires a straighteningof one ibent end of each key to permit extraction and removal .of the keys.

In the modification of Figures 6, 7 and ,8, the shank 7.0 is provided with a shaft receiving opening 71 at its top end and with a ledge 72, located intermediate the shank and immediately above .the head receiving end 74. The terminal end of the shank in this modification is fiat, providing theend surface 75 and said shank has side portions ,76 and 7,7 of a width-in excess of that of the center section whereby the shank end 74 has .a shape in cross section vsimulating an I. The hammer head 80, adapted for association with the-shank end 74 is centrally recessed in a longitudinal direction to provide a cavity $1 of complementary shape in plan. The-opening for the recess or cavity in the hammer head is located in the top wall 82 of the head and since the cavity terminates short of the bottom wall 83, the said bottom wall remains imperforate to provideprotection for the end of the shank.

The said end 740i the shank is provided with the key receiving grooves 84 and 85 formed in the side portions 76 :and 77, respectively, the said grooves receiving keys 86 and 87. Laterally extending openings 88 and 89 are formed in the hammer head, the same intersecting the cavity 81 within the head and also intersecting the channels 90 on respective sides of the head. The keys 86 and 87 .are inserted in the respective openings and grooves which align when the head is properly assembled on the shank and thus the keys lock the head thereon. Said keys may be held in place by cotter pins 9-1, which pins are received within the channels 90.

The invention is not to be limited to vor by details of construction of the particular embodiment thereof illustrated ;by .the drawings as various forms of the device will of course be apparent to those skilled in the art without departing from the spirit of the invention or the scope of the claims.

What is claimed is:

1. A rotary hammer of the character described comprising a shank having one end adapted to be pivotally mounted, the other end of the shank having a special shape for receiving a hammer head, said head having a cavity therein of a size and shape complementary to that of the shank end, said shank end having grooves formed in opposed walls thereof and said head having laterally extending openings therein communicating with the .cavity and aligning with the grooves respectively in theshank end when the parts are in assembled relation, and .a plurality of keys adapted for insertion in the aligned openings and grooves for releasably retaining the-hammer head in assembled relation on said shank end.

2. A rotary hammer of the character described comprising a shank having one end adapted to be pivotally mounted, the other end of the shank having a special shape in section for receiving and mounting a hammer head, a substantially rectangular head having a cavity therein of a size and shape in plan which is complementary to that of the shank end, opposite walls of the shank end each having a groove extending laterally and at right angles to the length of the shank, said hammer head having laterally extending openings therein intersecting the cavity and aligning with the grooves respectively in the shank end when the parts are in assembled relation, and a plurality of keys adapted for insertion in the aligned openings and grooves for releasably retaining the hammer head in assembled relation on the head.

3. A rotary hammer of the character described comprising a shank anda hammer head releasably fixed to the shank, said shank having an end portion certain opposed side walls of which are each provided with a groove, said hammer head having impact surfaces at respective ends, side surfaces, and top and bottom surfaces, the top surface of said head being formed with a cavity having a size andshape in plan complementary to the sectional shape of the shank end portion, the side surfaces of the head each having a pair of openings therein, said openings extending laterally and intersecting the cavity and aligning with the grooves respectively when the .parts are in assembled relation, and a pair of keys adapted for insertion in the aligned openings and grooves respectively for releasably retaining the hammer head in assembled relation on said shank end portion.

4. A hammer head for rotary mills and the like comprising a head portion substantially rectangular in shape and having top and bottom surfaces, side surfaces, and end impact surfaces, said head portion having a central cavity formed in the head from the top surface thereof, a hammer shank providing an end portion of the same cross-sectional shape as the cavity and adapted to fit in the cavity for mounting the head on the shank, said shank end portion having a groove in certain opposed side walls in right angle relation to the length of the shank ,end portion and adjacent the terminal end thereof, the head portion having openings therein extending from one side surface to the other and intersecting the central cavity, and keys adapted for location in the openings and grooves when in alignment for releasably retaining the head portion on the shank end portion.

References Cited in the ,file of this patent UNITED STATES PATENTS 1,170,370 Wald Feb. 1, 1916 1,491,418 Plaisted Apr. 22, 1924 1,693,058 Shelton Nov. 27, 1928 FOREIGN PATENTS 378,364 Italy Feb. 1, 1940 654,953 France Dec. 7, 1928 

